Means for reducing friable materials



Sept. 23; 1930. G. c. E. KEET 1,776,318

IEANS FOR REDUCING FRIABLE l MTERIALS Filed Aug. 22. 1929 f/aj Patented Sept. 1930 UNITED/STATES PATENT, OFFICE GABRIEL CHRISTIAN ERASMUS KEET, or KLERKSDORP, TRANSVAAL, SOUTH AFRICA I MEANS FOR REDUCING, raIABLn MATERIALS Application filed August 22,1929, SeriaLNo. 337,744, and in the union of South Africa June 27, 1929.

' This invention has forfits object to pro- .vide an improved means for reducing fri- Iable materials by combined grinding and crushing operations, which will be particu- L larly suitable for the reduction of ores and ment of the invention as applied toa mill for reducing ores and the like. I Referring to the drawings, 3 and 1 indi- 1 20 cate two grinding rolls, of which the working faces are respectively of concave and convex section. The roll 3 has formed in its periphery a V-groove 5, whilst the roll at is provided with a peripheral rim 6 ofinverted V-shape, the angle included by the sides of the V-groove 5 of the first roll, hereinafter termed the female roll, being equal to that f included by the sides of the rim 6 of the second roll, hereinafter termed the male roll.

two rolls should be unequal, as shown.

7 It is preferable that the diameters of the two rolls should be unequal, as shown,

The female roll 3 is revolubly mounted in suitable bearings 7 and driven by any convenient means, e. g, the gearing 8 from the driving-shaft 9, The male roll 5 is revolubly mounted. in bearings carried by the free ends of two rocking levers 10 which are ."connected by suitable links and levers with an eccentric 11 mounted upon the driving-shaft 9, the arrangement being such that rotation of the eccentric 11 operates to oscillate said rocking levers 10, thus moving the male roll 4 alternately towards] and away from the female'roll 3.

v Conveniently, the free end of the eccntric rod 11 may be connected to a second lever 12 having connected thereto. a link 13pivotally. connected to the mid-point 14 of a togmechanism It is, preferable that the diameters of the gle mechanism 15, 16, ofwhich one member 15 is pivoted to the free ends of the rocking levers 10 and of which the other member 16 is "secured tothe end or ends'of one or'more the toggle levers 15, 16, to oscillate the rockinglevers 10, the spring-pressedabutments 18 being arranged to take up'the thrust ofthe oscillatory motion, whilst also serving as shock absorbers in the event of unusually hard substances being fed into the mill. 1

Means maybe provided forregulating the stroke of the oscillatory roll 4, whilstthe mill is in operation, e. g, the fulcrum 20 of the 1ever 12 to which the eccentric rod llis conmanner as to permit of regulation of the throw of said lever 12. Conveniently the fulcrum 20 is slidably mounted withrelation to the lever 12 as shown, its position being regulated by an "adjusting screw '21. If desired,said fulcrum 20'may be adapted to be moved up to the point of connection 22 of the,

.nectedmay be adjustably mounted in such toggle link-13 with said lever 12, whereby the oscillating action imparted to the toggle a 15, 16, may be discontinued, if

desired.

In the female roll 3, the groove 5 betweenv the two grinding faces is deepened-sufficiently at 5 to prevent bottoming of the rim 6 of the male roll 4, thus ensuring thatthe grinding faces ofthe latter contact properly with those of the female roll 3, and so causing the 11 faces of the two rolls'to wear evenly.

In operation, material to be reduced is fed continuously by a suitable jigging conveyor or like feed (not shown) between the grinding faces of the two rolls where the combined crushing and grinding motion effectively reduces the material to a very'fine state. The reduced material then falls upon a screen (not shown) where there is provided suitable means for removing any insufficiently reduced particles and returning them to the feed of l I lrMeans for reducing friablematerials,

' comprising tWo complementary grinding rolls the working faces of which are respeccomprising two complementary "grinding tively in the form of a V groove and a rim of inverted V-shape, means for rotating the first roll, the second roll being rotatably mounted in the free ends of suitablero king levers and means for oscillating'said rocking levers Continuously in the direction of the 7 other roll.

- 2; Means of inverted V-shape, means for rotating the levers, and an eccentric mounted upon the .driving shaft and connected to said rocking levers.'- 1

3. Means for reducing friable materials,

comprising two complementary grinding rolls,-the Working faces of which are respectively in the form of a V-groove anda rim w of inverted .V-shape, means forv rotating the first roll, the second roll being rotatably v :mounted in the free ends vof suitable'rocking levers, an eccentric mounted upon the driv-.

,ing shaft and connected to said rocking les the stroke of vers, and means for regulating the rocking, 1e-vers.-

4;Means for reducing friable; materials,

rolls, the ,Working faces of WlllCl'l'fiIT-l respectivelyin the form of a V-groov'e and a rim of inverted V-shape, the V-grooveoftheiirst I roll being deepened to prevent bottoming of the rim of the second iroll, and means'for continuously oscillating the second rollin the direction'of the-other. r x

' 5. Means for reducingfriable materlals, comprisingtwo 7 complementary grinding -1-011s of which the Working faces; are respectively of concave and convex section, the sec vond rollbeing rotatably mounted in thefree ends of rotatinglevers, and eccentric, .a tog gle mechanism the mid-point of which is connected to said eccentric, one member of said toggle mechanism being connected to the free ends of said rocking levers hilst the other member is provided with spring pressed abutments.

In testimony whereof I have signed'my name to this specification at Johannesburg, Transvaal, Union of South Africa, this twenty-second day of July, 1929. s

GABRIEL CHRISTIAN ERASM US Rear.

for reducing friable materials, comprising two complementary grinding 7 rolls, the Working faces ofwhich are'respeo tively in the form-ofa V-groove and arim first roll, the second roll being rotatably mounted in the fre-e ends of suitable rocking 

